Z3 2.8 power increase

[Trackrod]

Any suggestions for the easiest way of improving the power output of a 2.8 Z3? Of all the Z3 variants the 2.8 has the lowest bhp per litre, so could easily cope with a bit more power, and, it does feel a bit sluggish for a 2.8.

[Pentoman]

The 2.8 was at that power because of German tax laws supposedly (bmw, merc, audi all the same bhp). Everyone says you put the intake (intake runners I think?) from the older 2.5 on. Presumably this is valid for a Z3 as well as a 328i.

The 2.8 seems fast enough not having driven one myself.

[StuB]

The earlier single vanos units can have the earlier 2.5 inlet manifold, the later twin vanos (known as TU) can't. It's reckoned to be good for 20-30 horses, mostly at the top end and would definitely need a re-map.

A supercharger is quite an effective upgrade though

[bergerac]

Chap on Z Roadster.net swears by supercharging. I think he posted a guide on the fitting procedure and the pros and cons thereafter. I love my 2.8 but always leaves me wandering what the Z3M must be like!

[David Godfrey]

bergerac said:

Chap on Z Roadster.net swears by supercharging. I think he posted a guide on the fitting procedure and the pros and cons thereafter. I love my 2.8 but always leaves me wandering what the Z3M must be like!

No idea how to make it quicker and my summary would be:

2.8 - Lovely

Z3M - Animal

Had both for quite some time and for me the Z3M is still the most ballanced RWD car I have driven to date just wish it did not eat tyres and Vanos units!

Edited by David Godfrey on Monday 21st July 16:12

[StuB]

bergerac said:

Chap on Z Roadster.net swears by supercharging. I think he posted a guide on the fitting procedure and the pros and cons thereafter.

That'll be Marc who's selling at the moment. His has more boost than mine and NOs, but only a tad quicker.

bergerac said:

I love my 2.8 but always leaves me wandering what the Z3M must be like!

Drive one then. They're really lovely, especially if on the right tyres, with strut braces fitted.

For me, the Q car status of a blown 2.8, a little more torque, cheaper servicing & insurance and a bullet proof motor held more appeal than buying an M.

I can upgrade quite easily too with more boost.

[Trackrod]

Supercharging sounds fun; anyone any ideas on the cost and affect on fuel consumption?

[StuB]

Mine cost c£5k, for NS racing to fit an ESS kit with a V2-SQ, kenlowe fan and a couple of other nits and bobs. No problems and good workmanship. This included a rolling road before and after at Power Engineering - 181 to 285!

More kits available now and the dollar exchange rate is brilliant, so it's a great time to buy.

ESS are also doing a twin screw s/c which gives max boost pretty much across the whole rev range! Graham (on here) has a Z4 with this kit - awesome.

Just don't do it if you want to sell the car on and make anything on it though

Edited to add, no negative impact on fuel unless you use the loud pedal, in which case I've seen c10 mpg on a trackday!

Edited by StuB on Tuesday 22 July 10:18